1. Field of the Invention
This invention relates generally to devices for supporting cables and, in particular, to hangers for securing cables to support structures.
2. Description of Related Art
Cable hangers are commonly used to secure cables to structural members of, for example, antenna towers and or along tunnel walls. Generally, each cable is attached to a structural member by cable hangers mounted at periodically-spaced attachment points.
Antenna towers and or tunnels may be crowded due to the multiplicity of cables required for signal-carrying. Over time, as systems are added, upgraded and or expanded, installation of additional cables may be required. To conserve space, it is desirable for each set of cable hangers to secure more than a single cable. Certain cable hangers have been constructed to secure multiple cables; other cable hangers have a stackable construction that permits multiple cable hangers to be interlocked extending outwardly from each mounting point/structural member. Stacked and multiple-cable-type cable hangers significantly increase the number of cables mountable to a single attachment point.
Prior vertically stackable multiple cable capable cable hangers, for example as disclosed in U.S. Patent Application Publication U.S. 2004/0061030 by Goodwin et al, required opening of the existing cable hanger to insert an additional cable into an unused cable holding space of the cable hanger. The prior cable hanger incorporated mounting hardware comprising a threaded rod that extended through each additional cable hanger in the vertical stack. Besides a significant materials expense, extending the cable hangers into stacked configurations requires initial installation of longer threaded rod than necessary and or exchange of mounting hardware that momentarily removes support for the existing cables, increasing installation complexity and costs.
The various single and multiple cable hangers of different capacities necessitate manufacturing, distribution and storage costs for a family of different hangers and similarly a range of different mounting hardware of varying lengths for each anticipated hanger stack configuration. Competition within the cable hanger market has focused attention on ease of use, reliability, expandability and overall reductions in manufacturing, distribution and installation costs.
Therefore, it is an object of the invention to provide a device that overcomes deficiencies in the prior art.